--- a/mercurial/commands.py	Wed Feb 03 04:37:04 2016 +0000
+++ b/mercurial/commands.py	Tue Feb 02 14:49:02 2016 +0000
@@ -6955,6 +6955,8 @@
     if rev is None or rev == '':
         rev = node
 
+    warndest = False
+
     with repo.wlock():
         cmdutil.clearunfinished(repo)
 
@@ -6976,6 +6978,7 @@
         if rev is None:
             updata = destutil.destupdate(repo, clean=clean, check=check)
             rev, movemarkfrom, brev = updata
+            warndest = True
 
         repo.ui.setconfig('ui', 'forcemerge', tool, 'update')
 
@@ -7002,7 +7005,8 @@
                 ui.status(_("(leaving bookmark %s)\n") %
                           repo._activebookmark)
             bookmarks.deactivate(repo)
-
+        if warndest:
+            destutil.statusotherdests(ui, repo)
     return ret
 
 @command('verify', [])

--- a/mercurial/destutil.py	Wed Feb 03 04:37:04 2016 +0000
+++ b/mercurial/destutil.py	Tue Feb 02 14:49:02 2016 +0000
@@ -218,3 +218,34 @@
             return revs.first()
 
     return None
+
+def _statusotherbook(ui, repo):
+    bmheads = repo.bookmarkheads(repo._activebookmark)
+    curhead = repo[repo._activebookmark].node()
+    if repo.revs('%n and parents()', curhead):
+        # we are on the active bookmark
+        bmheads = [b for b in bmheads if curhead != b]
+        if bmheads:
+            msg = _('%i other divergent bookmarks for "%s"\n')
+            ui.status(msg % (len(bmheads), repo._activebookmark))
+
+def _statusotherbranchheads(ui, repo):
+    currentbranch = repo.dirstate.branch()
+    heads = repo.branchheads(currentbranch)
+    l = len(heads)
+    if repo.revs('%ln and parents()', heads):
+        # we are on a head
+        heads = repo.revs('%ln - parents()', heads)
+        if heads and l != len(heads):
+            ui.status(_('%i other heads for branch "%s"\n') %
+                      (len(heads), currentbranch))
+
+def statusotherdests(ui, repo):
+    """Print message about other head"""
+    # XXX we should probably include a hint:
+    # - about what to do
+    # - how to see such heads
+    if repo._activebookmark:
+        _statusotherbook(ui, repo)
+    else:
+        _statusotherbranchheads(ui, repo)

--- a/tests/test-bisect2.t	Wed Feb 03 04:37:04 2016 +0000
+++ b/tests/test-bisect2.t	Tue Feb 02 14:49:02 2016 +0000
@@ -244,6 +244,7 @@
 
   $ hg up -C
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  3 other heads for branch "default"
 
 complex bisect test 1  # first bad rev is 9
 

--- a/tests/test-blackbox.t	Wed Feb 03 04:37:04 2016 +0000
+++ b/tests/test-blackbox.t	Tue Feb 02 14:49:02 2016 +0000
@@ -123,6 +123,7 @@
   $ hg update
   hooked
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  1 other heads for branch "default"
   $ hg blackbox -l 6
   1970/01/01 00:00:00 bob (*)> update (glob)
   1970/01/01 00:00:00 bob (*)> writing .hg/cache/tags2-visible with 0 tags (glob)

--- a/tests/test-bookmarks.t	Wed Feb 03 04:37:04 2016 +0000
+++ b/tests/test-bookmarks.t	Tue Feb 02 14:49:02 2016 +0000
@@ -573,6 +573,7 @@
   $ hg bookmark -r3 Y
   moving bookmark 'Y' forward from db815d6d32e6
   $ cp -r  ../cloned-bookmarks-update ../cloned-bookmarks-manual-update
+  $ cp -r  ../cloned-bookmarks-update ../cloned-bookmarks-manual-update-with-divergence
 
 (manual version)
 
@@ -617,6 +618,34 @@
   updating to active bookmark Y
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
 
+We warn about divergent during bare update to the active bookmark
+
+  $ hg -R ../cloned-bookmarks-manual-update-with-divergence update Y
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  (activating bookmark Y)
+  $ hg -R ../cloned-bookmarks-manual-update-with-divergence bookmarks -r X2 Y@1
+  $ hg -R ../cloned-bookmarks-manual-update-with-divergence bookmarks
+     X2                        1:925d80f479bb
+   * Y                         2:db815d6d32e6
+     Y@1                       1:925d80f479bb
+     Z                         2:db815d6d32e6
+     x  y                      2:db815d6d32e6
+  $ hg -R ../cloned-bookmarks-manual-update-with-divergence pull
+  pulling from $TESTTMP
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 2 changesets with 2 changes to 2 files (+1 heads)
+  updating bookmark Y
+  updating bookmark Z
+  (run 'hg heads' to see heads, 'hg merge' to merge)
+  $ hg -R ../cloned-bookmarks-manual-update-with-divergence update
+  updating to active bookmark Y
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  (activating bookmark Y)
+  1 other divergent bookmarks for "Y"
+
 test wrongly formated bookmark
 
   $ echo '' >> .hg/bookmarks
@@ -715,6 +744,7 @@
   $ hg up -C
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (leaving bookmark drop)
+  1 other heads for branch "default"
   $ hg sum
   parent: 2:db815d6d32e6 
    2

--- a/tests/test-conflict.t	Wed Feb 03 04:37:04 2016 +0000
+++ b/tests/test-conflict.t	Tue Feb 02 14:49:02 2016 +0000
@@ -232,6 +232,7 @@
 
   $ hg up -C
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  1 other heads for branch "default"
   $ printf "\n\nEnd of file\n" >> a
   $ hg ci -m "Add some stuff at the end"
   $ hg up -r 1
@@ -269,6 +270,7 @@
 
   $ hg up -C
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  1 other heads for branch "default"
   $ hg merge --tool :merge-local
   merging a
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved

--- a/tests/test-largefiles-cache.t	Wed Feb 03 04:37:04 2016 +0000
+++ b/tests/test-largefiles-cache.t	Tue Feb 02 14:49:02 2016 +0000
@@ -202,6 +202,7 @@
   large: data corruption in $TESTTMP/src/.hg/largefiles/e2fb5f2139d086ded2cb600d5a91a196e76bf020 with hash 6a7bb2556144babe3899b25e5428123735bb1e27 (glob)
   0 largefiles updated, 0 removed
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  2 other heads for branch "default"
   $ hg st
   ! large
   ? z

--- a/tests/test-largefiles-update.t	Wed Feb 03 04:37:04 2016 +0000
+++ b/tests/test-largefiles-update.t	Tue Feb 02 14:49:02 2016 +0000
@@ -68,6 +68,7 @@
 
   $ hg up
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  1 other heads for branch "default"
   $ hg debugdirstate --large --nodate
   n 644          7 set                 large1
   n 644         13 set                 large2
@@ -82,6 +83,7 @@
   n 644         13 set                 large2
   $ hg up
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  1 other heads for branch "default"
   $ hg debugdirstate --large --nodate
   n 644          7 set                 large1
   n 644         13 set                 large2

--- a/tests/test-merge-changedelete.t	Wed Feb 03 04:37:04 2016 +0000
+++ b/tests/test-merge-changedelete.t	Tue Feb 02 14:49:02 2016 +0000
@@ -111,6 +111,7 @@
 
   $ hg co -C
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  1 other heads for branch "default"
 
   $ hg merge --config ui.interactive=true <<EOF
   > c
@@ -171,6 +172,7 @@
 
   $ hg co -C
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  1 other heads for branch "default"
 
   $ hg merge --config ui.interactive=true <<EOF
   > foo
@@ -243,6 +245,7 @@
 
   $ hg co -C
   2 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  1 other heads for branch "default"
 
   $ hg merge --config ui.interactive=true <<EOF
   > d
@@ -301,6 +304,7 @@
 
   $ hg co -C
   2 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  1 other heads for branch "default"
 
   $ hg merge --tool :local
   0 files updated, 3 files merged, 0 files removed, 0 files unresolved
@@ -345,6 +349,7 @@
 
   $ hg co -C
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  1 other heads for branch "default"
 
   $ hg merge --tool :other
   0 files updated, 2 files merged, 1 files removed, 0 files unresolved
@@ -389,6 +394,7 @@
 
   $ hg co -C
   2 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  1 other heads for branch "default"
 
   $ hg merge --tool :fail
   0 files updated, 0 files merged, 0 files removed, 3 files unresolved
@@ -436,6 +442,7 @@
 
   $ hg co -C
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  1 other heads for branch "default"
 
   $ hg merge --config ui.interactive=True --tool :prompt
   local changed file1 which remote deleted
@@ -491,6 +498,7 @@
 
   $ hg co -C
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  1 other heads for branch "default"
 
   $ hg merge --tool :prompt
   local changed file1 which remote deleted
@@ -544,6 +552,7 @@
 
   $ hg co -C
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  1 other heads for branch "default"
 
   $ hg merge --tool :merge3
   local changed file1 which remote deleted

--- a/tests/test-merge-default.t	Wed Feb 03 04:37:04 2016 +0000
+++ b/tests/test-merge-default.t	Tue Feb 02 14:49:02 2016 +0000
@@ -33,6 +33,7 @@
 
   $ hg up
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  2 other heads for branch "default"
 
 Should fail because > 2 heads:
 

--- a/tests/test-merge-types.t	Wed Feb 03 04:37:04 2016 +0000
+++ b/tests/test-merge-types.t	Tue Feb 02 14:49:02 2016 +0000
@@ -155,6 +155,7 @@
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg up
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  1 other heads for branch "default"
   $ hg st
   ? a.orig
 
@@ -175,6 +176,7 @@
   keep (l)ocal, take (o)ther, or leave (u)nresolved? u
   0 files updated, 0 files merged, 0 files removed, 1 files unresolved
   use 'hg resolve' to retry unresolved file merges
+  1 other heads for branch "default"
   [1]
   $ hg diff --git
   diff --git a/a b/a

--- a/tests/test-merge5.t	Wed Feb 03 04:37:04 2016 +0000
+++ b/tests/test-merge5.t	Tue Feb 02 14:49:02 2016 +0000
@@ -24,6 +24,7 @@
   $ hg revert b
   $ hg update -c
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  1 other heads for branch "default"
   $ mv a c
 
 Should abort:

--- a/tests/test-strip.t	Wed Feb 03 04:37:04 2016 +0000
+++ b/tests/test-strip.t	Tue Feb 02 14:49:02 2016 +0000
@@ -287,6 +287,7 @@
 
   $ hg up
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  1 other heads for branch "default"
   $ hg log -G
   @  changeset:   4:264128213d29
   |  tag:         tip

--- a/tests/test-subrepo.t	Wed Feb 03 04:37:04 2016 +0000
+++ b/tests/test-subrepo.t	Tue Feb 02 14:49:02 2016 +0000
@@ -664,6 +664,7 @@
   $ cd ../t
   $ hg up -C # discard our earlier merge
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  2 other heads for branch "default"
   $ echo blah > t/t
   $ hg ci -m13
   committing subrepository t
@@ -677,6 +678,7 @@
 
   $ hg up -C # discard changes
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  2 other heads for branch "default"
 
 pull
 
@@ -718,6 +720,7 @@
   adding file changes
   added 1 changesets with 1 changes to 1 files
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  2 other heads for branch "default"
   $ cat t/t
   blah
 
@@ -1185,6 +1188,7 @@
   ? s/c
   $ hg update -C
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  2 other heads for branch "default"
   $ hg status -S
   ? s/b
   ? s/c

--- a/tests/test-transplant.t	Wed Feb 03 04:37:04 2016 +0000
+++ b/tests/test-transplant.t	Tue Feb 02 14:49:02 2016 +0000
@@ -409,6 +409,7 @@
 
   $ hg up -C
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  1 other heads for branch "default"
   $ rm added
   $ hg transplant --continue
   abort: no transplant to continue

--- a/tests/test-update-branches.t	Wed Feb 03 04:37:04 2016 +0000
+++ b/tests/test-update-branches.t	Tue Feb 02 14:49:02 2016 +0000
@@ -167,6 +167,7 @@
 
   $ norevtest '-c clean same'   clean 2 -c
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  1 other heads for branch "default"
   parent=3
 
   $ revtest '-cC dirty linear'  dirty 1 2 -cC